Senior IT Systems Administrator
Location: Gloucestershire, UK (On-Site)
Employment Type: Full-time, Mid-Senior level
About the Opportunity
Sanderson is collaborating with a leading global technology organisation that delivers mission-critical services in secure environments for government and national security clients. The team is expanding and seeking a skilled Senior IT Systems Administrator to join a high-performance environment supporting critical infrastructure operations.
In this role, you’ll work across multiple teams to ensure stability, performance, and compliance across enterprise systems — maintaining secure IT environments and helping drive continual service improvement through innovation and best practice.
Key Responsibilities
* Provide 1st and 2nd line technical support across complex IT environments
* Monitor system performance to ensure uptime, reliability, and efficiency
* Develop, maintain, and update system documentation
* Implement and enforce operational standards, policies, and procedures
* Support compliance initiatives and internal process improvements
Essential Skills & Experience
* Strong background in Windows Server Administration (2016/2019)
* Experience working to ITIL best practices
* Excellent organisational and time management skills
* Analytical mindset with a proactive approach to identifying risks and improvements
* Strong communication and collaboration skills, with a willingness to share and learn
Desirable Technologies & Experience
* Installation, upgrade, configuration, and support experience with Windows Server, AWS, and Azure
* Strong understanding of Active Directory (object creation, OU management, RBAC, DFS)
* Knowledge of virtualisation technologies: VMware, vSphere, vSAN, SCVMM, Hyper-V
* Familiarity with containerisation tools and technologies
* Networking fundamentals: TCP/IP, DHCP, DNS, LAN/WAN
* Scripting experience in PowerShell
* Awareness of McAfee EPO/ENS security tools
Security Clearance Requirements
Due to the nature of the work, candidates must be eligible for national security clearance. To meet this requirement, applicants must:
* Be sole British citizens (dual nationality is not permitted)
* Have not spent more than 30 consecutive days outside the UK in the past 10 years
* Have no criminal record
* Have no significant financial irregularities (e.g. bankruptcy, unpaid debt)
Unfortunately, candidates who do not meet these criteria cannot be considered for this position.
Why You’ll Enjoy Working Here
* Competitive salary and comprehensive benefits package
* Hybrid working model balancing flexibility and collaboration
* Career growth opportunities through continuous learning and development
* Work on high-impact, nationally significant projects
* Inclusive, people-first culture focused on wellbeing and professional excellence